Fluid burner



Jan. 10, 1939. A. CLARKSON 2,143,259

FLUID BURNER Filed June 21, 1937 Imfen b1:

. $111M [Ya/k902i Patented Jan; 10, 1939 UNITED STATES PATENT OFFICEFLUID BURNER Alick Clarkson, Elmhurst, 111.,

Application June 21, 1937, Serial No. 149,466

9 Claims.

This invention relates to certain new and useful improvements in anapparatus for burning fluid fuel. This application is a continuation inpart of the copending application of Alick Clarkson, Serial No. 99,736,filed September 8, 1936.

This burner assembly is especially designed for use as the heatingapparatus of a steam generator of the water-tube type, such as shown forexample in said copending parent application, although the improvedburner assembly could be used for heating other types of heatexchangeapparatus.

Briefly described, the atomized oil or other fluid fuel is projectedinto the combustion chamber in a fire-pot that is mounted within an airchamber into which the combustion air is forced under pressure. The fuelenters the fire-pot through a reduced opening in one end thereof, theother end of the fire-pot being open to discharge the products ofcombustion into the heatexchange apparatus. The fire-pot is providedwith auxiliary features and air-inlets, and is so formed as to controland direct the supply of pre-heated combustion air to secure the maximumcombustion and efficiency of operation and to properly direct the hotgases into the heatexchanger.

The principal object of this invention is to provide an improved burnerapparatus of the type briefly described hereinabove and disclosed morein detail in the specification which follows.

Another object is to provide an improved form of firepot for afluid-fuel burner.

Another object is to provide improved means for supplying combustion airto a fluid-fuel burner.

Another object is to provide an improved means for controlling thecombustion of fuel in a heating apparatus of the type set forth.

Other objects and advantages of this invention will be more apparentfrom the following detailed description of one approved form ofapparatus constructed and operating according to the principles of thisinvention.

The accompanying drawing is a central vertical section through theimproved burner assembly and a portion of a heat-exchange apparatus withwhich the same is used.

At A is indicated the upper portion of a steam generating apparatus ofthe water-tube type, said apparatus being more fully disclosed in theparent application hereinabove referred to, and at B is indicated theheater assembly which in the form here shown is mounted on top ofgenerator A, so as to direct its heated gases or products of combustiondownwardly into the central heating space I within the generator.

The generator A comprises a plurality of substantially helical pipeloops 2, 3, 4, 5, 6 and I arranged coaxially about the central vertical5 axis a: so as to enclose the central heating space I. The outer coilsserve as pre-heating .coils whereas the inner coils are vaporizingcoils. The pipe coils are successively connected at al ternate ends ofthe bank of coils so that feed- 10 water forced under pressure into theouter pipe coil 2 will pass successively through the several coils and amixture of water and steam will be discharged from the innermost coil 7.The successive turns or loops of adjacent coils are prefl5 erablystaggered with relation to one another, as shown, so that the hot gasesfrom central heating chamber I will be forced to take a sinuous pathbetween the several pipe turns, thus insuring a maximum surface contactwith the M coils and a maximum heat exchange. The gases, relieved of thegreater portion of their heat, finally reach the outer annular space 2within the outer casing 9 and flow out through a flue, indicated at Ill.As has already been noted, other forms of heat-exchange apparatus couldbe used to extract the heat from the hot gases delivered from theimproved heating assembly, indicated generally at B.

This assembly B comprises a flame-ring ii 3a which partially closes theupper end of the gen erator and directs the heated gases thereinto, thisring including an upper disc or plate M which rests on the generatorcasing and a centrally downwardly projecting substantially cylindricalportion l3 surrounding the central inlet passage M. The casing indicatedgenerally at It encloses the air-supply chamber I6. Casing l5 comprisesthe annular bottom wall ll resting on flame-ring H, the substantiallycylindrical side wall It and top wall ill, the casing being completelyclosed except for the inlet port 29, into which air under pressure isdelivered from conduit 2! leading from the blower 22.

The atomizer 23 (here shown by way of ex- 4.5 ample if liquid fuel isused), or other device for delivering the fluid-fuel is supported oncasing 15 and comprises a discharge nozzle 24 projecting into the casing(preferably in line with the vertical axis x). This nozzle is preferablymounted in an upwardly domed portion 25 of easing l5 which also supportsthe electrical ignition device 26. Atomizer 23 is preferably of the typeincluding a valve which opens only under a certain predetermined minimumpressure, so that no 5 fluid wfll be discharged from nozzle 24 unlessthe fuel is supplied under suitable pressure.

The fire-pot indicated generally at 21 is supported centrally within airchamber l6, and preferably symmetrically about the central vertical axisx. This fire-pot is open at its lower end to communicate with the inletopening I leading to the generator. The fire-pot is preferably metallicand comprises a substantially cylindrical side wall, and is partiallyclosed at the top by the wall or flange 28 which curves upwardly andinwardly and then downwardly to the upper central inlet 29 which is ofconsiderably less diameter than the fire-pot and through which openingthe atomized fuel is projected from nozzle 24, as indicated by lines 30.An air-directing ring 3| is interposed betweemthe lower end of fire-pot21 and flame-ring Air-ring 3| is supported above the flame-ring byspacers 32 so as to provide an annular air passage 33 through which airis projected inwardly and downwardly through passage M in theflame-ring. The flrepct 21 is supported above the air-ring 3| byinterposed spacers 34 so as to provide an annular passage 35. The uppersurface of air-ring 3| is curved, as indicated at 36, so as to directcombustion air through passage 35 upwardly within the fire-pot adjacentthe side walls thereof. This air flow is then directed downwardly againby the curved upper wall 28 of the fire-pot so as to provide eddycurrents within the fire-pot, all as indicated by the arrows.

A stabilizing member 31, preferably in the form of a frustum of a cone,is interposed between nozzle 24 and the upper inlet to the fire-pot, andsurrounds a primary ignition zone. This stabilizing cone comprises anouter conical ring 38 supported at its larger lower end from thefire-pot by struts 39 so as to provide an intermediate inlet spaceflflfor combustion air. A second inner and upper conical ring 4|, preferablyprovided with an upper outwardly extending horizontal flange 42, issupported from ring 38 by inter- -mediate spacers so as to provide apassage 63 intermediate the cone members for confining a blanket of airtherebetween. The stabilizing cone can be provided with a series of airopenings, indicated at M,

It will be noted that the air supply in chamber l6 completely surroundsthe fire-pot 27 so that this air will be highly pre-heated beforeentering the combustion space.

Combustion air flows in through the upper opening in the stabilizingcone 3! and also through the passage B0 below this cone so as to providea substantially static and protected ignition zone within the cone formaintaining the flame at this point. The atomized fuel is projecteddownwardly through this ignition zone and through opening 29 into theflre pot, as indicated by lines 39. The outer initially vaporized fuelparticles are ignited and burned in this ignition zone, and the heatthus provided in this zone serves to fully vaporize the remainder of thefuel before it is projected into the combustion space within thefire-pot. Combustion air flows into the fire-pot through upper opening29 and also upwardly within and adjacent the side walls of the pot fromlower passages 35, as already described. This producescirculating aircurrents within the fire-pot including a whirling vortex ring below theupper flange 28 so that the combustion is very largely completed withinthis combustion chamber. Additional combustion air flows inwardly anddownwardly through passage 33 below air-ring 3| (and additionalairpassages 45 may also be provided in air-ring 3|) so that allcombustion is practically completed before the hot gases are delivereddownwardly into the heating space I within the generator. It will benoted that the combustion air is highly pre-heated before entering thecombustion zone, and also all metallic parts are protected both insideand out by blankets of incoming air so that these parts will not besubjected to a destructively high temperature. Air holes 46 may also beprovided in flange |2 of the air-ring H to provide a flow of cooling airbehind the cylindrical flange l3 of the air ring.

It has been found that this improved burner assembly accomplishespractically complete combustion of the fuel, and functions steadily andin a highly efficient manner so as to provide a maximum quantity of heatfrom the quantity of fuel burned.

I claim:

1. In combination with a heat-exchange apparatus formed with an internalheating Space having an open end through which hot gases are dischargedinto the heating space, a burner assembly comprising a casing enclosingan air supply chamber beyond the open end of the heating space, meansfor forcing air into the chamber, a flame-ring positioned in the openend of the heating space and encircling a passage leading from thechamber to the heating space, a fire-pot positioned in said chamber,said fire-pot having an open inner end directed toward the passagethrough the flame-ring and having an annular flange partially closingits outer end and encircling a central inlet opening of less diameterthan the fire-pot, a nozzle projecting within the casing in position todischarge fluid-fuel through the inlet opening of the fire-pot, andannular means positioned between the inner open end of the fire-pot andthe flame-ring but spaced from both to direct air inwardly through theflame-ring and also into the fire-pot adjacent the wall thereof andtoward the partially closed outer end of the pot.

2. In combination with a heat-exchange apparatus formed with an internalheating space having an open end through which hot gases are dischargedinto the heating space, a burner assembly comprising a casing enclosingan air supply chamber beyond the open end of the heating space, meansfor forcing air into the chamber, a flame-ring positioned in the openend of the heating space and encircling a passage leading from thechamber to the heating space, a firepot positioned in said chamber, saidfire-pot having an open inner end directed toward the passage throughthe flame-ring and having an annular flange partially closing its outerend and encircling a central inlet opening of less diameter than thefire-pot, a nozzle projecting within the casing in position to dischargefluid-fuel through the inlet opening of the fire-pot, and annular meanspositioned between the inner open end of the fire-pot and the flame-ringbut spaced from both to direct air inwardly through the flame-ring andalso into the fire-pot adjacent the wall thereof and toward thepartially closed outer end of the pot, said annular flange at the outerend of the fire-pot being inwardly concave so as to redirect toward theinner open end of the pot the air flowing outwardly along the wall ofthe pot.

3. In combination with a heat-exchange apparatus formed with an internalheating space having an open end through which hot gases are dischargedinto the heating space, a burner assembly comprising a casing enclosingan air supply chamber beyond the open end of the heating space, meansfor forcing air into the chamber, a flame-ring positioned in the openend of the heating space and encircling a passage leading from thechamber to the heating space, a firepot positioned in said chamber, saidfire-pot having an open inner end directed toward the passage throughthe flame-ring and having an annular flange partially closing its outerend and encircling a central inlet opening of less diameter than thefire-pot, a nozzle projecting within the casing in position to dischargefluid-fuel through the inlet opening of the fire-pot, annular meanspositioned between the inner open end of the fire-pot and the flame-ringflame-ring and also into the fire-pot adjacent the wall thereof andtoward the partially closed outer end of the pot, and perforated meansfor supporting the flame-ring within the open end of the heating spaceso that an annular passage is provided outside the ring through which anauxiliary flow of cooling air from the supply chamber passes around theouter side of the flame-ring into the heating space.

4. In combination with a heat-exchange apparatus formed with an internalheating space having an open end through which hot gases are dischargedinto the heating space, a burner assembly comprising a casing enclosingan air supply chamber beyond the open end or the heating space, meansfor forcing air into the chamber, a fire-pot positioned in the chamberand having an inner open end directed toward and opposed to the open endof the heating space, the fire-pot being partially closed at its outerend by an annular flange encircling a central inlet opening of lessdiameter than the firepot, a nozzle projecting within the casing inposition to discharge fluid-fuel through the inlet opening of thefire-pot, and annular means positioned between the opposed open ends ofthe pot and heating space to direct air into the heating space and alsointo the fire-pot adjacent the wall thereof and toward the partiallyclosed end of the pot.

5. In combination with a heat-exchange apparatus formed with an internalheating space having an open end through which hot gases are dischargedinto the heating space, a burner assembly comprising a casing enclosingan air supply chamber beyond the open end of the heating space, meansfor forcing air into the chamber, a fire-pot positioned in the chamberand having an inner open end directed toward and opposed to the open endof the heating space, the fire-pot being partially closed at its outerend by an annular flange encircling a central inlet opening of lessdiameter than the firepot, a nozzle projecting within the casing inposition to discharge fluid-fuel through the inlet opening of thefire-pot. and annular means positioned between the opposed open ends ofthe pot and heating space to direct air into the heating space and alsointo the fire-pot adjacent the wall thereof and toward the partiallyclosed end of the pot, said annular fiange at the outer end of the potbeing inwardly concave so as to redirect toward the inner open end ofthe pot the air flowing outwardly along the wall of the pot.

6. In combination with a heat-exchange apbut spaced from both to directair inwardly through the,

paratus formed with an internal heating space having an open end throughwhich hot gases are discharged into the heating space, a. burnerassembly comprising a casing enclosing an air supply chamber beyond theopen end of the heating space, means for forcing air into the chamber, afire-pot positioned in the chamber and having an inner open end directedtoward and opposed to the open end of the heating space, the fire-potbeing partially closed at its outer end by an annular flange encirclinga central inlet opening of less diameter than the fire-pot, a nozzleprojecting within the casing in position to'. discharge fluid-fuelthrough the inlet opening of'the fire-pot, annular means positionedbetween the opposed open ends of the pot and heating space to direct airinto the heating space and also into the fire-pot adjacent the wallthereof and toward the partially closed end of the pot, and an annularstabilizing member positioned between the nozzle and the inlet to thefire-pot but spaced from both to enclose a primary ignition space. a

7. In combination with a heat-exchange apparatus formed with an internalheating space having an open end through which hot gases are dischargedinto the heating space, a burner assembly comprising a casing enclosingan air supply chamber beyond the open end of the heating space, meansfor forcing air into the chamber, a ,flre-pot positioned in the chamberand having an inner open end directed toward and opposed to the open endof the heating space, the fire-pot being partially closed at its outerend by an annular flange encircling a central inlet opening of lessdiameter than the fire-pot; a nozzle projecting within the casing inposition to discharge fluid-fuel through the inlet opening of thefire-pot, annular means positioned between the opposed open ends of thepot and heating space to direct air into the heating space and also intothe fire-pot adjacent thewall thereof and toward the partially closedend of the pot, and an annular stabilizing member positioned between thenozzle and the inlet to the fire-pot but spaced from both to enclose aprimary ignition space, said stabilizing member being in the form of afrustum of a cone with its larger end directed toward the inlet to thefirepot.

8. In combination with a heat-exchange apparatus formed with an internalheating space having an open end through which hot gases are dischargedinto the heating space, a burner assembly comprising a casing enclosingan air supply chamber beyond the open end of the heating space, meansfor forcing airinto the chamber, a fire-pot positioned in the chamberand having an inner open end directed toward and opposed to the open endof the heating space, the fire-pot being partially closed at its outerend by an annular flange encircling a central inlet opening of lessdiameter than the fire-pot, a nozzlev projecting within the casing inposition to discharge fluid-fuel through the inlet opening of thefire-pot, annular means positioned between the opposed open ends of thepot and heating space to direct air into the heating.

space and also into the fire-pot adjacent the wall thereof and towardthe partially closed end of the pot, and an annular stabilizing memberpositioned between the nozzle and the inlet to the fire-pot but spacedfrom both to enclose a primary ignition space, the stabilizing memberbe- 1o concave toward the open end of the pot, means for forcing airinto the pot through the inlet opening and also in the reverse directionthrough the discharge opening along the inner cylindrical wall of thepot, this latter air flow being redlrected by the concave flange to forman annular vortex within the pot, and means for projecting fuel into thepot through the inlet opening and centrally into the vortex.

.ALICK CLARKSON.

